Elevator for a scraper

ABSTRACT

A scraper, the scraper adapted to be pulled by a tractor. The scraper includes a bowl, with a cutting blade attached to the lower front of the open bowl. An elevator is present across the front of the open bowl, the elevator including a multiplicity of flights on an endless conveyor. The conveyor will scoop up dirt it accumulates at the front of the bowl and lift it up for dumping into the bowl. Applicants provide a block for adjustably setting the position of the frame of the elevator so that it is adjacent to cutting blade.

[0001] This application claims priority from U.S. Provisional Application No. 60/382,711 filed May 23, 2002, and incorporates the specifications herein by reference.

FIELD OF THE INVENTION

[0002] This invention relates to an elevator mechanism for a tractor scraper vehicle and, more particularly, to a mechanism for allowing the upward and downward, forward and backward movement of the elevator frame.

BACKGROUND OF THE INVENTION

[0003] Elevating scrapers are provided for earth moving purposes. Most elevating scrapers have an open front bowl with rear supporting wheels and a scraper blade at the lower front edge of the bowl. The blade loosens soil as the scraper is pulled, by a tractor, over the ground. An elevator is provided at the open front of the bowl for moving dirt accumulated about the scraper blade up and away from the blade and into the bowl. The elevator is an endless conveyor type elevator that is positioned at the open front end of the bowl. The elevator is a continuous chain conveyor carrying a multiplicity of flights, the conveyor extending upwardly from the blade and forming a forward wall of the bowl.

[0004] If the elevator is rigidly mounted on the scraper bowl, frequent stalling and damage occurs due to the elevator engaging relatively immoveable objects, such as a large boulder or a rock which is too large to be lifted by the elevator into the bowl. To eliminate this problem, elevators have been mounted on a floating mount in such a way that the elevator can be pushed up to override large boulders or stones, or other obstructions and can reposition itself when the obstruction is passed. Linkage arrangements exist with respect to these floating mounts. One such linkage arrangement is interconnected with a pivotal floor portion such that when the floor portion is pivoted to drop the load in the bowl, the elevator is moved forward and upward to clear a large opening in the bowl for dropping the load. Guide and stop mechanisms and linkage mechanisms are provided for engaging the elevator to the bowl which allow the elevator to move up and forward in floating arrangement from a predetermined, preselected position above the cutting blade.

[0005] Most elevating scrapers have either a two-point suspension or a four-point suspension which allows some upward movement. Another linkage will force the elevator to move slightly forward on its upward tract in an effort to force the elevator down by using the weight of the elevator itself. The prior art elevator designs would allow the elevator to be raised or lowered to accommodate a wide variety of soil types and conditions.

[0006] The prior art designs have been limited in the ability to pick up soil without lowering the cutting blade into the soil due to the inability of the elevator to move in front of the cutting blade. The present invention is directed at allowing the elevator to pick up the soil without actually cutting into the soil. According to the present invention, a multimode mechanism is mounted to the scraper bowl by means of a linkage to the elevator frame. For general or normal dirt moving, the elevator is placed in the rear position by unbolting a pivoting slider block which will move the elevator frame upward and behind the cutting blade. The elevator height can be adjusted in this position since an eccentric rectangular height adjustment block is part of the linkage assembly. Only downward movement of the front of the elevator frame is limited, upward movement to allow the elevator to clear obstacles is unrestricted.

[0007] For finish dirt moving, the pivoting adjuster or slider block is moved, allowing the elevator to move down and in front of the cutting blade until the lowest level of the elevator flights are at or even below the cutting blade. This adjustment allows the face of the elevator flights or bars to be at about the same level as the cutting blade. Therefore, it is possible for the elevator to lift the soil up into the bowl without actually cutting into the soil with the cutting blade of the bowl.

[0008] The prior art devices typically provide only a single preselected undisturbed position of the elevator with respect to the cutting blade, but provide for the ability of the elevator to “float” a limited distance forward and above the preselected height. The result of such limitations in the prior art is that, while the scraper may be effective for many general earth moving conditions, its full range of potential, especially in finish work, is not realized. For example, some earth moving jobs will often leave windrows heaped up by several passes over a scraped surface. For the scraper to pick up these windrows, the job is slightly more delicate and, with the windrows and dirt that is accumulated from previous scraping, there is less concern for striking a large object such as a rock. In such a situation, it may be desirable to lower and move diagonally forward the elevator with respect to the cutting blade until the lowest flights are about the level of the cutting blade. Moving the elevator diagonally forward and down allows the scraper to remove the windrow without cutting into the previously scraped surface.

[0009] Prior art elevators include a frame, typically rectangular with a bottom axle (or axle stubs) and a top axle (or axle stubs) for mounting a pair of chain driven sprockets on the top and a pair of rollers on the bottom. The top axle is driven and the chains have a multiplicity of transverse flights attached thereto, to provide an endless conveyor for moving dirt from above the cutting blade up and into the open top of the bowl. The frame of the elevator in the prior art devices is typically attached by four points and four mounting arms to the bowl. The mounting arms are capable of pivoting where they join the frame and where they join the bowl. A stop block is provided adjacent the lower edge of the frame such that the frame may rest at a preselected position above the cutting blade. The preselected position of the lower end of the elevator is determined by the length of the two lower mounting arms and the position and height of the stop blocks. However, the stop blocks are only capable of adjusting the elevator vertically relative to the cutting edge. Thus, the bottom end of the elevator may ride up and over obstacles and in any “at rest” position it is fixed vertically with respect to the cutting blade.

SUMMARY OF THE INVENTION

[0010] The present invention is directed to overcoming one or more of the problems set forth above. According to the present invention, an adjustment means is provided to adjustably set the front of an elevator between a multiplicity of positions along an axis extending forward and downward and upward and rearward from the horizontal while allowing the front of the elevator to float. Applicants' present invention provides, additionally, for preselecting an elevator position along an axis about perpendicular to the aforementioned axis. Applicants' present invention provides for a floating capability wherein the front of the elevator can climb up and over an obstacle met in its path.

[0011] Another feature of applicants invention is an elevator frame that has non-parallel side members for improved strength.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1A is a side elevational view showing the general arrangement of the tractor, scraper and elevator.

[0013]FIG. 1 is a side elevational view showing the elevator mounted adjustably to the bowl and showing the two positions of the elevator, a first position allowing the lowest flights of the elevator to be at about the level of the cutting blade and a second position which positions the lowest flights of the elevator above the cutting blade. The distance (vertical) between the two positions is preferably in the range of 2″ to 18″.

[0014]FIG. 2 is an exploded perspective view of the elevator assembly of Applicants' present invention, including the structure for adjustably mounting the elevator assembly to the bowl so that the elevator can move between the two pre-selected positions set forth in FIG. 1.

[0015]FIGS. 3A and 3B are side elevational views of the adjuster assembly of Applicants' present invention. In FIG. 3A, the adjuster mechanism will position the elevator in a finish dirt moving mode where the lowest flights of the elevator are at about the level of the cutting blade. The general dirt moving mode is illustrated in FIG. 3B and this will position the lower flights of the elevator above the cutting blade.

[0016]FIG. 4 is a side perspective view of the adjuster assembly of Applicants' present invention.

[0017]FIG. 5 illustrates in the manner in which the adjuster assembly engages the lower arms and the lower arms engage the elevator frame and rest on a stop block.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] Reference is made to FIGS. 1A-5 for an understanding of the manner in which scrapers work in general and, more specifically, the novel arrangement, structure, features and function of Applicants' invention. Applicants' novel invention includes an earth moving, tractor drawn scraper. The scraper comprises an open front bowl having a cutting blade at a forward and bottom edge thereof, and a pair of wheels. The scraper includes means, such as linkage, to engage the bowl to the tractor to pull the bowl across earth. An elevator for attachment to the open front of the bowl is provided, the elevator including a frame, the frame having a front cross member, the elevator including an endless chain driven conveyor, the conveyor having a multiplicity of flights thereon, the elevator including means to mount the conveyor to the frame thereof. To this arrangement, Applicants provide a novel adjustment means to mount the frame of the elevator to the bowl so as to set the frame front cross member at a preselected one of a multiplicity of positions, the multiplicity of positions defining an axis trending down and forward and up and back with respect to the cutting blade.

[0019] The figures illustrate Applicants' novel scraper, including Applicants' novel adjustment means. The figures illustrate a tractor (10) and a trailer (12), with means (14) to engage the tractor to the trailer. The tractor will pull the trailer around, and the trailer includes a scraper (16), wheels (18), the scraper including a bowl (20) and an elevator assembly (hereinafter elevator) (22). The function of the tractor is to pull the trailer and the engagement means to attach a trailer to the tractor so that the trailer maintains three axis movement with respect to the tractor.

[0020] The scraper (16) is provided with a cutting blade (24) at the forward bottom end. The cutting blade (24) will scrape dirt and the elevator will lift the dirt and move it up and back, dumping it in the open bowl. When the open bowl is filled with scraped dirt, it will be emptied.

[0021] The elevator frame (28) typically includes a rear cross member (28A), a front cross member (28B) and two side members (28C) to form a generally trapezoidal structure. An axle (30) is mounted on axle mounting stanchions (32) to elevator frame (28), typically adjacent rear cross member (28A). The axle includes drive sprockets (30A) (only top right shown) engaged with hubs (30B and 30C), the drive sprockets for powering a chain of the elevator as set forth in more detail below. A lower elevator stub/spindle assembly (48) is provided including hubs 48A to carry the chains.

[0022] Thus, it is seen that at the four corners of the generally rectangular frame, there are a pair of axle mounted drive sprockets for engaging a pair of chains, one chain being driven by the left top sprocket (34A) and the other by the top right sprocket. The flight assembly (46) that is carried on the two drive sprockets and two hubs and includes a multiplicity of transversely mounted individual flights (46A) on the two chains (48B).

[0023] Thus, it is seen that the elevator assembly may include a frame to which is attached the chains, which include a flight assembly carried on an upper pair of drive sprockets and a lower pair of hubs, the upper pair of sprockets being carried by an axle (30) which is driven by a gear box (not shown).

[0024] The elevator frame and the flight assembly is adjustably mounted to the bowl (12). This is usually done through four points of attachment. Those four points are: bottom lower left and bottom lower right elevator mounting stubs (40) and a pair of upper right and upper left mounting stubs (36). The mounting stubs are attached, typically to the side members of the elevator frame, by bosses, stanchions or some other mounting means. These four points (two pairs of mounting points) are mounted, in turn, to upper left and upper right elevator arms (34) and lower left and lower right elevator arms (38) (note at this point that Applicants have provided, in FIG. 2, a drawing on which the left side of the frame structure is exploded and the right side shows structure connected up, and further, has missing some structure that is properly on the both left and right, for example only one of the drive sprockets, the upper left one is shown, but it is understood that there are two.)

[0025] The lower and upper elevator arms are attached to the frame rotatably. The elevator arms have near ends (34A and 38A) and removed ends (34B and 38B). The near ends are rotatably mounted to the wall of the body of through Applicants' unique adjuster assembly (26) for setting the elevator with respect to the bowl. The adjuster assembly (26) includes a mounting plate (26A) having holes drilled for the receipt of fasteners therein. Typically, there are four holes, here illustrated as (26B), (26C), (26D) and (26E). There is an adjuster assembly engaged with each side of the frame. The adjuster assembly includes pivoting plate (27). Pivoting plate (27) has a stub (27A) attached thereto for rotatably mounting near ends of the lower elevator arms (38A) thereto. The three holes on pivoting plate (27) are illustrated as 27D, 27B, and 27C. Pivoting plate (27) mounts to mounting plate (28) at hole (26D), the mounting plate in turn mounts to the walls of the bowl. By engaging pivoting plate hole (27D) with hole (26E) on mounting plate with a fastener such as a nut and bolt, the upper two holes on the pivoting plate may selectively engage either mounting plate hole pair (26E and 26B) or mounting plate hole pair (26E and 26C). This can be done because the distance between the upper two holes on pivoting plate (27) is the same as the distance that holes (26C and 26B) are adjacent to hole (26E). Further, it can be seen that the effect of mounting pivoting plate (27) to the forward set of holes on mounting plate (hole pair 26E and 26C) is to shift the lower elevator arms (38), and therefore frame (28) of elevator assembly down and forward (here reference is made to FIGS. 3A and 3B which illustrate the two positions). In the forward and down position (compared to the up and back position), finishing earth moving work is provided for. The up and back position (see FIG. 3B) is provided for general earth moving work. Rear stop plate (50) will block the movement of pivoting plate (27) and position the plate in alignment with holes (26B) and (26E). Front stop plates (52) will block pivoting plate (27) and align it with holes (26C) and (26E).

[0026] Note that upper arms (34) are rotatably mounted to both the frame and the inner walls of the bowl in a conventional manner. Note also that through removed ends of the lower arms may contain an eccentric rectangular block, here rotating block (42) which will rest on lower arm support plate (44) welded to the sidewall to the bowl. Eccentric rotating block (42) may rotate to adjustably set front cross member (48B) forward and up or down and back with respect to the cutting edge.

[0027] Turning back to FIG. 1, note that when the pivoting plate is in the forward position, the arc (Af) transcribed by the flights of the conveyor as they reach the lowest point is equal to the cutting blade level (CBL). This would be the proper position of the elevator when finished work, such as cleaning up windrows is being performed. Again with reference to FIG. 1, it is seen that when pivoting plate (27) is in the rearward position, the arc (Ag) transcribed by the flights of the elevator as they pass through their lowest point is above the cutting blade level (CBL).

[0028] Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention. 

I claim:
 1. An earth moving trailer drawn scraper, comprising: a bowl having a cutting blade; wheels for engaging the bowl; an elevator, the elevator including a frame, the elevator including an endless chain driven conveyor having a multiplicity of flights; and adjustment means engaged to the bowl to mount the frame to the bowl adapted to shift the frame so as to selectively set the lowest of flights either in a first operating position at about the level of the cutting blade or at the second operating position, a second operating position locating the lowest of the flights above the level of the cutting blade.
 2. The earth moving trailer drawn scraper of claim 1 wherein the vertical distance between the lowest of the flights when the frame is in the first position and the lowest of the flights when the frame is in the second position is in the range of 2″ to 18″.
 3. The earth moving trailer drawn scraper of claim 1 wherein the adjustment means includes a pair of arms engaged at a forward end to the frame and at a rearward end to a plate that is adapted to be pivotally mounted to the bowl.
 4. The earth moving trailer drawn scrapper of claim 3 wherein the rearward ends of the arms are rotatably mounted to the plate.
 5. The earth moving trailer drawn scraper of claim 3 further including a pair of support plates mounted to the bowl and wherein the forward ends of the arms are adapted to rest on support plates.
 6. The earth moving trailer drawn scraper of claim 5 wherein the forward ends of the arms are adapted to be adjustably located with respect to the support plates.
 7. The earth moving trailer drawn scraper of claim 5 wherein the forward ends of the arms have blocks eccentrically mounted thereto for adjustably positioning the arms on the support plates.
 8. The earth moving trailer drawn scraper of claim 3 wherein the adjustment means also include means to limit the pivoting of the pivotal plate to a pre-selected range.
 9. The earth moving trailer drawn scraper of claim 4 wherein the adjustment means also include means to limit the pivoting of the pivotal plate to a pre-selected range.
 10. The earth moving trailer drawn scraper of claim 3 wherein the vertical distance between the lowest of the flights when the frame is in the first position and the lowest of the flights when the frame is in the second position is in the range of 2″ to 18″.
 11. The earth moving trailer drawn scraper of claim 1 wherein the frame includes side members and the side members are not parallel. 